Publicaciones 2011-2020

@article{RN372,
title = {Experimental and Theoretical Reduction Potentials of Some Biologically Active Ortho-Carbonyl Para-Quinones},
author = { M. Martinez-Cifuentes and R. Salazar and O. Ramirez-Rodriguez and B. Weiss-Lopez and R. Araya-Maturana},
url = {/brokenurl#<Go to ISI>://WOS:000404517800075},
doi = {10.3390/molecules22040577},
issn = {1420-3049},
year = {2017},
date = {2017-01-01},
journal = {Molecules},
volume = {22},
number = {4},
abstract = {The rational design of quinones with specific redox properties is an issue of great interest because of their applications in pharmaceutical and material sciences. In this work, the electrochemical behavior of a series of four p-quinones was studied experimentally and theoretically. The first and second one-electron reduction potentials of the quinones were determined using cyclic voltammetry and correlated with those calculated by density functional theory (DFT) using three different functionals, BHandHLYP, M06-2x and PBE0. The differences among the experimental reduction potentials were explained in terms of structural effects on the stabilities of the formed species. DFT calculations accurately reproduced the first one-electron experimental reduction potentials with R-2 higher than 0.94. The BHandHLYP functional presented the best fit to the experimental values (R-2 = 0.957), followed by M06-2x (R-2 = 0.947) and PBE0 (R-2 = 0.942).},
keywords = {aprotic-solvents, aqueous-solution, batteries botrytis-cinerea, computational cyclic density density-functional electrochemistry, electron-transfer, functional ion models, p-benzoquinone, potential, properties, quinones, redox semiquinone, solvation theory, voltammetry},
pubstate = {published},
tppubtype = {article}
}

@article{RN321,
title = {Protonation Sites, Tandem Mass Spectrometry and Computational Calculations of O-Carbonyl Carbazolequinone Derivatives},
author = { M. Martinez-Cifuentes and G. Clavijo-Allancan and P. Zuniga-Hormazabal and B. Aranda and A. Barriga and B. Weiss-Lopez and R. Araya-Maturana},
url = {/brokenurl#<Go to ISI>://WOS:000381500900086},
doi = {UNSP 1071, 10.3390/ijms17071071},
issn = {1422-0067},
year = {2016},
date = {2016-01-01},
journal = {International Journal of Molecular Sciences},
volume = {17},
number = {7},
abstract = {A series of a new type of tetracyclic carbazolequinones incorporating a carbonyl group at the ortho position relative to the quinone moiety was synthesized and analyzed by tandem electrospray ionization mass spectrometry (ESI/MS-MS), using Collision-Induced Dissociation (CID) to dissociate the protonated species. Theoretical parameters such as molecular electrostatic potential (MEP), local Fukui functions and local Parr function for electrophilic attack as well as proton affinity (PA) and gas phase basicity (GB), were used to explain the preferred protonation sites. Transition states of some main fragmentation routes were obtained and the energies calculated at density functional theory (DFT) B3LYP level were compared with the obtained by ab initio quadratic configuration interaction with single and double excitation (QCISD). The results are in accordance with the observed distribution of ions. The nature of the substituents in the aromatic ring has a notable impact on the fragmentation routes of the molecules.},
keywords = {antitumor assignment, basicities, c-13 carbazole, chemistry complete derivatives, dft, gas-phase hydroquinone ionization, mass molecules, nmr-spectra, qcisd, quinones, respiration, spectrometry, tumor-cell},
pubstate = {published},
tppubtype = {article}
}

@article{RN215,
title = {Intramolecular Hydrogen Bond in Biologically Active O-Carbonyl Hydroquinones},
author = { M. Martinez-Cifuentes and B. Weiss-Lopez and L.S. Santos and R. Araya-Maturana},
url = {/brokenurl#<Go to ISI>://WOS:000340036200041},
doi = {10.3390/molecules19079354},
issn = {1420-3049},
year = {2014},
date = {2014-01-01},
journal = {Molecules},
volume = {19},
number = {7},
pages = {9354-9368},
abstract = {Intramolecular hydrogen bonds (IHBs) play a central role in the molecular structure, chemical reactivity and interactions of biologically active molecules. Here, we study the IHBs of seven related o-carbonyl hydroquinones and one structurally-related aromatic lactone, some of which have shown anticancer and antioxidant activity. Experimental NMR data were correlated with theoretical calculations at the DFT and ab initio levels. Natural bond orbital (NBO) and molecular electrostatic potential (MEP) calculations were used to study the electronic characteristics of these IHB. As expected, our results show that NBO calculations are better than MEP to describe the strength of the IHBs. NBO energies (Delta E-ij((2))) show that the main contributions to energy stabilization correspond to LP ->sigma* interactions for IHBs, (O1O2)-O-center dot center dot center dot-H-2 and the delocalization LP ->pi* for O-2-C-2 = C-alpha(beta). For the (O1O2)-O-center dot center dot center dot-H-2 interaction, the values of Delta E-ij((2)) can be attributed to the difference in the overlap ability between orbitals i and j (F-ij), instead of the energy difference between them. The large energy for the LP O-2 ->pi* C-2 = C-alpha(beta) interaction in the compounds 9-Hydroxy-5-oxo-4,8, 8-trimethyl-1, 9(8H)-anthracenecarbolactone (VIII) and 9,10-dihydroxy-4,4-dimethylanthracen-1(4H)-one (VII) (55.49 and 60.70 kcal/mol, respectively) when compared with the remaining molecules (all less than 50 kcal/mol), suggests that the IHBs in VIII and VII are strongly resonance assisted.},
keywords = {ab-initio, bond bond, chemistry, derivatives, dft, diels-alder electrostatic hydrogen hydroquinone, inhibitors, molecular molecules, natural orbital, potential, quinones, radicals reaction, resonance, respiration, tumor-cell},
pubstate = {published},
tppubtype = {article}
}

@article{RN190,
title = {2-Phenylaminonaphthoquinones and Related Compounds: Synthesis, Trypanocidal and Cytotoxic Activities},
author = { I. Sieveking and P. Thomas and J.C. Estevez and N. Quinones and M.A. Cuellar and J. Villena and C. Espinosa-Bustos and A. Fierro and R.A. Tapia and J.D. Maya and R. Lopez-Munoz and B.K. Cassels and R.J. Estevez and C.O. Salas},
url = {/brokenurl#<Go to ISI>://WOS:000341293300010},
doi = {10.1016/j.bmc.2014.07.030},
issn = {0968-0896},
year = {2014},
date = {2014-01-01},
journal = {Bioorganic & Medicinal Chemistry},
volume = {22},
number = {17},
pages = {4609-4620},
publisher = {2014 Elsevier Ltd.},
abstract = {A series of new 2-aminonaphthoquinones and related compounds were synthesized and evaluated in vitro as trypanocidal and cytotoxic agents. Some tested compounds inhibited epimastigote growth and trypomastigote viability. Several compounds showed similar or higher activity and selectivity as compared with current trypanocidal drug, nifurtimox. Compound 4l exhibit higher selectivity than nifurtimox against Trypanosoma cruzi in comparison with Vero cells. Some of the synthesized quinones were tested against cancer cells and normal fibroblasts, showing that certain chemical modifications on the naphthoquinone moiety induce and excellent increase the selectivity index of the cytotoxicity (4g and 10). The results presented here show that the anti-T. cruzi activity of 2-aminonaphthoquinones derivatives can be improved by the replacement of the benzene ring by a pyridine moiety. Interestingly, the presence of a chlorine atom at C-3 and a highly lipophilic alkyl group or aromatic ring are newly observed elements that should lead to the discovery of more selective cytotoxic and trypanocidal compounds.},
keywords = {activity, antimalarial antineoplastic assay, benzocarbazolequinones, biological colorimetric cruzi, cytotoxicity, derivatives, electronic evaluation, general-route, properties, quinones, t. trypanosoma-cruzi},
pubstate = {published},
tppubtype = {article}
}